package com.yan.controller;

public class TeerTest {


    public static void main(String[] args) {

        String abc="";
        String abcd="null";
        String abcde=null;

        System.out.println("abc"+abc);
        System.out.println("abcd"+abcd);
        System.out.println("abcde"+abcde);
        System.out.println("===========================");





        Double abcde1=null;

        System.out.println("abcde1"+abcde1);
        System.out.println("===========================");


        Integer abcde12=null;

        System.out.println("abcde12"+abcde);
        System.out.println("===========================");


        Long abc1=null;
        System.out.println("abc1"+abc);




    }










}
